Dynamo-electric machine.



T. S. ALLEN.

DYNAMO ELECTRIC MACHINE.

APPLICATION mm APR. 15. 1910.

Patented Sept. 5, 1916.

" f STATES PATENT OFFICE.

mom's. um, 01' IILWAUKEE, WISCONSIN, ASSIGI'OB, BY alarm-rs, TO muracmmacomm, AOOBPOBA'I'IOI OI nmwm.

nnmo-nmc'rarc nacrmm Specification of Letters mm.

Patented Sept. 5, 1916.

' Application filed April15,1910. Q1181 Io. "5,020.

To all whom it may concern Beit known that I, Tnouas S. ALLEN a citizenof the United States, residing at Milwaukee, in the county' of Milwaukeeand State of Wisconsin, have invented certain new and usefulImprovements in Dynamo- Electric Machines, of which the following is afull, clear, and exact specification.

This invention relates to dynamo-electric machines, and particularly torevolving field members of high speed alternators, such asturbo-generators.

In certain types of dynamo-electric machines, and particularly inrotating field members of high speed machines, parts of the coils areunder high stresses whlch tend to distort and displace thecoils, andparticularly the side portions thereof. These stresses are especiallygreat in high speed rotating field members having a small number ofpairs of poles, for in such machines the centrifugal force acting oncertain parts of a coil may be divided into two 'components, oneof whichis at right angles to the faceof the'pole and tends to shift the coillaterally from the pole, and this component may be as large or evenlarger than the component which is parallel to the axis of the pole andis resisted by the pole tips.

To support the coils and to prevent their displacement at high speeds,coil bracing members have been employed, and these bracing members, eachof which supports and braces the sides of the coils of two adjacentpoles, are usually retained in position by fastening devices extendinginto the core of the rotating member. Such bracing members have not beensatisfactory in all respects for the reason that they add to the weightof. the machine, are frequently diflicult to apply to the coils, and toadjust or tighten, and it is often the case that the means for fasteningthese bracing members in position materially weakens the core.

The object of the present invention is to provide coil supporting meanswhich relieves the coils of the st tending to shift them outwardly orlaterally from the pole, which is inexpensive, light in weight, and canbe easily applied tothe coils.

In carrying out my invention, I bind the coils firmly to the poles so asto relieve the side portions of the coils of the stresses, andpreferably band wire is employed for this purpose, each coil-beingwrapped at differing material, are placed lengthwise of ,the coil on theexterior thereof, and this band wire is wrapped tightly about thesestrips so that all portions of the coil are held against lateraldisplacement.

The invention may be further brieflysummarized as consisting in certaincombinations and arrangements of parts which. will be described in thespecification and set forth in the appended claims.

Reference is had to the accompanying sheet of drawings wherein- Figure 1is a side elevation of a dynamoelectric machine having a rotating fieldmember, the coils of which are supported and braced in accordance withmy invention; Flg. 2 is an enlarged side view of one of the fieldmagnets; and, Fig. 3 is a transverse sectional view substantially alongthe line 3-3 of Fig. 2.

In the figures of the drawing, 10 represents the stationary element ofthe machine, which in this case is an armature, and 11 represents as awhole, the rotary element which in this case is a rotary field member.The rotary member includes a core 12,which is mounted upon a shaft 13,and field magnets 14, each comprising a core 15 and a coil 16, which maybe formed of any suitable conductor and with any number of layers, butas shown in Fig. 3, is formed of several layers of square conductor 17.

The radial displacement of the coils due to that component of thecentrifugal force acting on each part of a coil, parallel to the axis ofthe pole is resisted by pole tips or other polar projections 18 providedat the free end of the pole, but unless means is provided for relievingthe sides of the coils of the stresses, they may be displaced or shiftedlaterally or outwardly away from the pole, and when a coil is built upof several layers of square conductor, as shown in Fig. 3, the turns'atthe inner end of the pole will tend to telescope with ect to the turnsat the outer end. To secure y hold all portions of the coils againstlateral displacement, I bind each coil ata number of spaced omts in itslength by several turns of tigh y wrapped band wire 19, and pref-'erably, I employ between the band wire and the coil longitudinallyextending strips 20 which are arranged at the corners of the coil, andalong the sides and ends thereof, the strips being preferably spacedapart and forming passageways therebetween, as shown in the drawings,this construction leaving the portions of the coil surface uncovered bystrips open to the atmosphere. with this latter arrangement and with thebinding material laid over, =the strips at spaced points, as shown inthe drawings, the bearing of the binding material is distributed overthe full axlal length of the coil with little or no danger of cuttinginto the same, and a considerable portion of the coil surface is open tothe atmosphere, a condition which promoteseflicient ventilation andcooling of the coil. These strips may be formed of metal, providing theexterior of the coil is covered with a layer of coating of -insulation,or they may be formed of insulating material, such as fiber. The turnsof wire in each group, three of which are shown in the drawings, may besoldered together opposite each of the strips 20, and the free ends ofeach group will be securely fastened so that the band wire will notbecome loose at any speed at which the rotary field member may beoperated.

It will be seen that the coil supporting and bracing means which I haveprovided tending in the general direction of the turns of said coil.

2. In a dynamo-electric machine, a rotary element havlng field magnetscomprising radial poles and coils mounted thereon,

means for preventing radial displacement of said coils, spaced stripsextending longitudinally of the coils at theexterior thereof, certain ofsaid strips being disposed at the corners of said coils and being madeup of parts disposed at an angle to each other and engaging adjacentsides of the coils, and banding material wrapped about said strips anddisposed in a plurality of spaced sections to prevent lateraldisplacement of portions of said coils.

Milwaukee, -Wis, April 11, 1910.

In testimony whereof I aflix my signature,

in the presence of two witnesses.

THOMAS S. ALLEN.

Witnesses:

CHAS. L. BYRON, Ros. E. LEOLL.

